Teaching and understanding evolution is challenging because students must synthesize several biological processes that are traditionally taught separately. We developed a set of free online lessons and activities centered on a single evolutionary phenomenon – why deer mice have different fur colors in different subpopulations – to help high school students better understand how these different biological processes, operating at different scales, work together to influence a single organismal trait. Through scaffolded investigations, guiding questions, model building, and pointed analysis, students learn how ecology, cellular biology, molecular biology, genetic inheritance, and population genetics all work together to influence a shift in fur color over time. Using an innovative multilevel simulation, students manipulate and examine these different processes from the population level all the way down to the DNA level. In this article, we describe the lessons and materials we have developed for high school biology students. We outline the learning goals and highlight the major components of the technology and activities in each lesson. We then provide information on how to access our curricular and support materials, and conclude with user feedback from our pilot testing.